Sensor pada Robot Pemadam Api - TUGINO

Tugino, ST MT
tugino@sttnas.ac.id
Jurusan Teknik Elektro
STTNAS Yogyakarta
Sensor pada Robot Pemadam Api
{
{
{
{
{
{
Tugino, ST MT
Flame Detektor
Speed sensor
Ultra sonic sensor
Flame Navigator
LDR sensor
IR distance sensor
STTNAS Yogyakarta
2
1
{
Robot AB-Tech ( Juara 2 KRCI Reg 3)
Tugino, ST MT
STTNAS Yogyakarta
3
SISTEM PENGENDALIAN
Sensor jarak kiri
LCD
Flame detektor
Motor kanan
Sensor jarak kanan
Driver PWM
Motor kiri
Sensor jarak depan
Mikrokontroller
AT89S51
Driver
Motor kipas
Sensor jarak serong
kanan
Motor Servo
Sensor jarak serong
kiri
Tugino, ST MT
Sensor garis putih
STTNAS Yogyakarta
4
2
sensor
{
{
{
{
Flame Detektor
Flame
Navigator
Ultrasonic
sensor
Sensor line
tracker
Tugino, ST MT
STTNAS Yogyakarta
5
Flame Detektor
Tugino, ST MT
STTNAS Yogyakarta
6
3
Ultrasonic sensor
Tugino, ST MT
STTNAS Yogyakarta
7
White floor Detector
Tugino, ST MT
STTNAS Yogyakarta
8
4
Sensor pada
Robot AIBO
Tugino, ST MT
STTNAS Yogyakarta
9
Sensor pada Robot
Shadow Biped
Tugino, ST MT
STTNAS Yogyakarta
10
5
Buku Acuan
{
{
Tugino, ST MT
Sensors for mobile robots: theory and
applications, H. R. Everett, A. K. Peters
Ltd, C1995, ISBN: 1-56881-048-2
Handbook of Modern Sensors: Physics,
Designs and Applications, 2nd edition,
Jacob Fraden
Fraden, AIP Press/Springer
Press/Springer, 1996.
1996
ISBN 1-56396-538-0.
STTNAS Yogyakarta
11
Websites acuan
{
{
{
{
{
{
{
http://www.omega.com/ (sensors + handhelds)
http://www.extech.com/ (hand-helds)
http://www.agilent.com/ (instruments,
enormous)
http://www.keithley.com/ (instruments, big)
http://www.tegam.com/ (instruments, small)
http://www.edsci.com/
p //
/ ((optics
p
++))
http://www.pacific.net/~brooke/Sensors.html
(comprehensive listing of sensors etc. and
links)
Tugino, ST MT
STTNAS Yogyakarta
12
6
Apa itu sensor ?
{
{
Sensor – adalah peralatan
electrical/mechanical/chemical
/
/
y
yang
g
memetakan suatu keadaan ke dalam betuk
besaran pengukuran
Masing-masing sensor didasarkan pada prinsip
perpindahan - mengkonversi dari energi satu
ke energi yang lain
Tugino, ST MT
STTNAS Yogyakarta
13
Sensor yang dimiliki manusia
{
{
{
{
{
Tugino, ST MT
Penglihatan
g
: mata ((optics,
p
, light)
g )
Pendengaran : Telinga (acoustics,
sound)
Sentuhan : Kulit (mechanics, heat)
Bau : Hidung (vapor-phase
chemistry)
Rasa : Lidah (liquid-phase
chemistry)
STTNAS Yogyakarta
14
7
Tranduser Elektronik
{
{
{
{
{
{
{
Thermistor: temperature-to-resistance
Electrochemical: chemistry-to-voltage
Photocurrent: light intensity-to-current
Pyroelectric: thermal radiation-to-voltage
Humidity: humidity-to-capacitance
Length (LVDT: Linear variable differential
transformers) : position-to-inductance
Microphone: sound pressure-to-<anything>
Tugino, ST MT
STTNAS Yogyakarta
15
Klasifikasi Sensor
{
Proprioception (Internal ) v.s.
Exteroceptive (external )
z
z
{
Aktif v.s. Pasif
z
z
{
{
Mengukur
M
k nilai
il i sistem
i t
iinternal
t
l robot
b t contoh
t h
level battery , posisi roda , sudut sendi , dll,
Mendeteksikondisi lingkungan/objek
Memancarkan energi contoh radar, sonar
Menerima energi contoh camera
Kontak v.s. non-kontak
Visual v.s. non-visual
z
vision-based sensing, image processing,
video camera
Tugino, ST MT
STTNAS Yogyakarta
16
8
Proprioceptive Sensors
{
Encoders, Potentiometers
z
{
Gyroscopes
z
z
{
Mengukur rata2 perubahan sudut
fiber-optic (saat ini ), magnetic (dulu )
Compass
z
{
Mengukur sudut dengan mengetahui
perubahan resisten atau pencacah optik
Mengukur posisi
GPS: Mengukur lokasi di bumi
Tugino, ST MT
STTNAS Yogyakarta
17
Electromagnetic Spectrum
Visible Spectrum
700 nm
Tugino, ST MT
400 nm
STTNAS Yogyakarta
18
9
Sensors Based on EM Spectrum
{
Radio and Microwave
z
z
{
RADAR: Radio Detection and Ranging
Microwave radar: insensitive to clouds
Coherent light
z
z
z
all photons have same phase and wavelength
LASER: Light Amplification by Stimulated
Emission of Radiation
LASER RADAR: LADAR - accurate ranging
Tugino, ST MT
STTNAS Yogyakarta
19
Sensors Based on EM Spectrum
{
Light sensitive
z
z
eyes, cameras, photocells etc.
Operating principle
{
{
{
CCD - charge coupled devices
photoelectric effect
IR sensitive
z
Local Proximity Sensing
{
{
z
Infrared LEDs (cheap, active sensing)
usually
s all lo
low resolution
esol tion - normally
no mall used
sed fo
for
presence/absence of obstacles rather than
ranging, operate over small range
Sense heat differences and construct images
Human detection sensors
{ night vision application
{
Tugino, ST MT
STTNAS Yogyakarta
20
10
General Classification (1)
Tugino, ST MT
STTNAS Yogyakarta
21
General Classification (2)
Tugino, ST MT
STTNAS Yogyakarta
22
11
Sensors Used in Robot
Gas Sensor
Gyro
Accelerometer
Pendulum Resistive
Tilt Sensors
Metal Detector
Piezo Bend Sensor
Gieger-Muller
Radiation Sensor
Pyroelectric Detector
UV Detector
Resistive Bend Sensors
CDS Cell
Resistive Light Sensor
Digital Infrared Ranging
Pressure Switch
Miniature Polaroid Sensor
Limit Switch
Touch Switch
Mechanical Tilt Sensors
IR Sensor w/lens
IR Pin
Diode
Thyristor
IR Reflection
Sensor
Magnetic Sensor
Magnetic Reed Switch
IR Amplifier Sensor
Hall Effect
Magnetic Field
Sensors
Polaroid Sensor Board
IRDA Transceiver
Lite-On IR
Remote Receiver
Radio Shack
Remote Receiver
Tugino, ST MT
IR Modulator
Receiver
Solar Cell
Compass
STTNAS Yogyakarta
Compass
24
Piezo Ultrasonic Transducers
12
Sensors Used in Robot
Resistive sensors
z Sensors lekukan, potentiometer, resistive photocells, ...
{ Tactile sensors
z contact switch, bumpers…
{ Infrared sensors
z Reflective, proximity, distance sensors…
{ Ultrasonic Distance Sensor
{ Inertial Sensors (measure the second derivatives of position)
z Accelerometer, Gyroscopes,
{ Orientation Sensors
z Compass, Inclinometer
{ Laser range sensors
Tugino,
ST MT GPS, …
STTNAS Yogyakarta
{
Vision,
{
25
Resistive Sensors
13
Resistive Sensors
Bend Sensors
• Resistance = 10k to 35k
• As the strip is bent, resistance increases
Resistive Bend Sensor
Potentiometers
• Can be used as position sensors for sliding
mechanisms or rotating shafts
• Easy to find, easy to mount
Potentiometer
Light Sensor (Photocell)
• Good for detecting direction/presence of light
• Non-linear resistance
• Slow response to light changes
Tugino, ST MT
Photocell
R is small when brightly illuminated
STTNAS Yogyakarta
27
Aplikasi Resistive Bend Sensor
Tugino, ST MT
STTNAS Yogyakarta
28
14
Applications
Sensor
{
{
{
Measure bend of a joint
Wall Following/Collision
Detection
Sensors
Sensor
Weight Sensor
Tugino, ST MT
STTNAS Yogyakarta
29
Inputs for Resistive Sensors
V
Voltage divider:
R1
You have two resisters, one
is fixed and the other varies,
varies
as well as a constant voltage
Vsense
R2
V
=
R1 + R2
Vsense
R2
A/D converter
micro
V
+
-
Binary
Threshold
Di i l I/O
Digital
Comparator:
If voltage at + is greater than at -,
digital high out
Tugino, ST MT
STTNAS Yogyakarta
30
15
Infrared Sensors
{
Intensity based infrared
z
z
z
{
Modulated Infrared
z
z
z
{
Reflective sensors
Easy to implement
susceptible to ambient light
Proximity sensors
Requires modulated IR signal
Insensitive to ambient light
Infrared Ranging
z
z
z
Distance sensors
Short range distance measurement
Impervious to ambient light, color and reflectivity of object
Tugino, ST MT
STTNAS Yogyakarta
31
Intensity Based Infrared
Break-Beam sensor
Reflective Sensor
voltage
Increase in ambient light
raises DC bias
time
voltage
• Easy to implement (few components)
• Works very well in controlled environments
• Sensitive to ambient light
time
Tugino, ST MT
STTNAS Yogyakarta
32
16
IR Reflective Sensors
{
Reflective Sensor:
z
z
z
z
{
Applications:
z
z
z
{
Emitter IR LED + detector photodiode/phototransistor
Phototransistor: the more light reaching the
phototransistor, the more current passes through it
A beam of light is reflected off a surface and into a detector
Light usually in infrared spectrum, IR light is invisible
Object detection,
Line following, Wall tracking
Optical encoder (Break-Beam sensor)
Drawbacks:
z
Susceptible to ambient lighting
{
z
z
Provide sheath to insulate the device from outside lighting
Susceptible to reflectivity of objects
Susceptible to the distance between sensor and the object
Tugino, ST MT
STTNAS Yogyakarta
33
DETEKTOR GARIS PUTIH
TONE DETEKTOR
Untuk pengaktifan pada start awal
Tugino, ST MT
STTNAS Yogyakarta
34
17
White floor Detector
Tugino, ST MT
STTNAS Yogyakarta
35
Modulated Infrared
{
Modulation and Demodulation
z
z
z
z
z
Flashing a light source at a particular frequency
Demodulator is tuned to the specific frequency of light
flashes (32kHz
flashes.
(32kHz~45kHz)
45kHz)
Flashes of light can be detected even if they are very week
Less susceptible to ambient lighting and reflectivity of
objects
Used in most IR remote control units, proximity sensors
Negative true logic:
Detect = 0v
No detect = 5v
Tugino, ST MT
STTNAS Yogyakarta
36
18
IR Proximity Sensors
amplifier
{
Proximity Sensors:
z
z
z
z
{
bandpass filter
integrator
limiter
demodulator
comparator
Requires a modulated IR LED, a detector module with built-in modulation decoder
Current through the IR LED should be limited: adding a series resistor in LED driver
circuit
Detection range: varies with different objects (shiny white card vs. dull black object)
Insensitive to ambient light
Applications:
z
z
z
Rough distance measurement
Obstacle avoidance
Wall following, line following
Tugino, ST MT
STTNAS Yogyakarta
37
IR Distance Sensors
{
Basic principle of operation:
z
IR emitter + focusing lens + position-sensitive detector
Modulated IR light
Location of the spot on the detector corresponds to
the distance to the target surface, Optics to covert
horizontal distance to vertical distance
Tugino, ST MT
STTNAS Yogyakarta
38
19
IR Distance Sensors
{
Sharp GP2D02 IR Ranger
z
z
z
z
z
Distance range: 10cm (4") ~ 80cm (30").
Moderately
ode a e y reliable
e ab e for
o distance
d s a ce measurement
easu e e
Immune to ambient light
Impervious to color and reflectivity of object
Applications: distance measurement, wall
following, …
Tugino, ST MT
STTNAS Yogyakarta
39
IR Distance Detector
Sharp GP2D12
Tugino, ST MT
STTNAS Yogyakarta
40
20
SENSOR INFRA RED
Sensor jarak menggunakan sensor INFRA RED
Diagram blok detektor dinding
FLAME NAVIGATOR
Basic Navigation Techniques
• Relative Positioning (called Dead-reckoning)
– Information required: incremental (internal)
{
{
Velocity
heading
– With this technique the position can be updated with
respect to a starting point
– Problems: unbounded accumulation error
•
Absolute Positioning
– Information Required: absolute (external)
– Absolute references (wall, corner, landmark)
– Methods
{
{
{
{
{
Tugino, ST MT
Magnetic Compasses (absolute heading, earth’s magnetic
field)
Active Beacons
Global Positioning Systems (GPS)
Landmark Navigation (absolute references: wall, corner,
artificial landmark)
Map-based positioning
STTNAS Yogyakarta
42
21
Dead Reckoning
Cause of unbounded accumulation error:
Systematic Errors:
a)) U
Unequall wheel
h l diameters
di
t
b) Average of both wheel diameters
differs from nominal diameter
c) Misalignment of wheels
d) Limited encoder resolution,
sampling rate, …
Nonsystematic Errors:
a) Travel over uneven floors
b) Travel over unexpected objects on
the floor
c) Wheel-slippage due to : slippery
floors; over-acceleration, fast turning
(skidding), non-point wheel contact
with the floor
Tugino, ST MT
STTNAS Yogyakarta
43
Sensors used in navigation
{
Dead Reckoning
z
Odometry
{
(monitoring the
wheel revolution to compute the
offset from a known starting
position)
{
{
{
Encoders,
Potentiometer,
Tachometer, …
External Sensors
z
z
z
z
z
z
– Inertial Sensors
Compass
p
Ultrasonic
Laser range sensors
Radar
Vision
Global Positioning
System (GPS)
((measure th
the second
d derivative
d i ti
of position)
{
{
Tugino, ST MT
Gyroscopes,
Accelerometer, …
STTNAS Yogyakarta
44
22
Motor Encoder
Incremental Optical Encoders
- calibration ?
• Relative position
light
g sensor
light emitter
- direction ?
- resolution
l ti ?
decode
circuitry
grating
Tugino, ST MT
STTNAS Yogyakarta
46
23
Velocity Detector
Tugino, ST MT
{
STTNAS Yogyakarta
47
Incremental p
position encoder
z
uses a single line that alternates
black/white
two slightly offset sensors produce
outputs as shown below
{ detects motion in either direction, pulses
are
a
e counted
cou ted to determine
dete
e absolute
abso ute
position (which must be initially reset)
{
Tugino, ST MT
STTNAS Yogyakarta
48
24
counting techniques
Inductive sensor
Tugino, ST MT
Opto-switch sensor
STTNAS Yogyakarta
49
Sensor Kecepatan Motor
Tampak
Samping
Tampak
Depan
Bentuk
Gelombang
25
DETEKTOR PUTARAN RODA
Detektor putaran roda
menggunakan roda pencacah dan
rangkaian opto
opto--coupler
Pancaran sinar infra merah yang
diterima oleh fototransistor, jika
terhalang maka output bernilai
tegangan 5 Volt ( logika 1 ), dan
sebaliknya jika tidak terhalang
m k output
maka
tp t kkeluaran
l r n ttegangan
g ng n 0
Volt ( logika 0 ).
Tugino, ST MT
STTNAS Yogyakarta
51
Incremental Optical Encoders
Quiz 1:
If there are 100 lines in the grating, what is the smallest
detectable change in motor-shaft angle?
light emitter/detector
Quiz 2:
How could you augment a grating-based (relative) encoder
in order to detect the direction of rotation?
Tugino, ST MT
STTNAS Yogyakarta
52
26
Incremental Optical Encoders
- calibration ?
• Relative position
light
g sensor
light emitter
- direction ?
- resolution
l ti ?
decode
circuitry
grating
A
A
A leads B
B
B
Tugino, ST MT
STTNAS Yogyakarta
53
Incremental Optical Encoders
• Incremental Encoder:
light sensor
- direction
light emitter
decode
circuitry
- resolution
grating
• It generates pulses proportional to the rotation speed of the shaft.
• Direction can also be indicated with a two phase encoder:
A
B
Tugino, ST MT
A leads B
STTNAS Yogyakarta
54
27
Incremental
• Incremental
Encoder:
Optical Encoders
A
B
A leads B
ChA
ChB
DIR
Encoder pulse and motor direction
Tugino, ST MT
{
STTNAS Yogyakarta
55
Absolute position encoders
{
sensor is an array of photodiodes
Incremental p
position encoder
Tugino, ST MT
STTNAS Yogyakarta
56
28
Absolute Optical Encoders
• Used when loss of reference is not possible.
• Gray codes: only one bit changes at a time ( less uncertainty).
• The information is transferred in parallel form (many wires are necessary).
Tugino, ST MT
Binary
Gray Code
000
000
001
001
010
011
011
010
100
110
101
111
110
101
111
100
STTNAS Yogyakarta
57
Other Odometry Sensors
• Resolver
It has two stator windings
g ppositioned
at 90 degrees. The output voltage is
proportional to the sine or cosine
function of the rotor's angle. The
rotor is made up of a third winding,
winding C
• Potentiometer
= varying
resistance
Tugino, ST MT
STTNAS Yogyakarta
58
29
Flame Detektor
Tugino, ST MT
STTNAS Yogyakarta
59
Range Finder
{
{
Time of Flight
The measured p
pulses typically
yp
y come
form ultrasonic, RF and optical energy
sources.
z
z
z
z
D=v*t
D = round-trip distance
v = speed of wave propagation
t = elapsed time
Sound = 0.3 meters/msec
{ RF/light = 0.3 meters / ns (Very difficult
to measure short
distances 1-100
Tugino, ST MT
STTNAS Yogyakarta
60
meters)
{
30
{
Ultrasonic Sensors
Basic principle of operation:
z
z
z
Emit a quick burst of ultrasound (50kHz), (human
hearing: 20Hz to 20kHz)
M
Measure
the
th elapsed
l
d time
ti
until
til the
th receiver
i
indicates
i di t
that an echo is detected.
Determine how far away the nearest object is from the
sensor
ƒD=v*t
D = round-trip distance
v = speed of propagation(340 m/s)
t = elapsed time
Bat, dolphin, …
Tugino, ST MT
STTNAS Yogyakarta
61
Sensor Ultra Sonic
Transmiter 40 kHz
Reciever
Tugino, ST MT
STTNAS Yogyakarta
62
31
Sensor Ultra Sonic
Transmiter 40 kHz
Reciever
Tugino, ST MT
STTNAS Yogyakarta
63
Ultrasonic sensor
Tugino, ST MT
STTNAS Yogyakarta
64
32
Ultrasonic Sensors
{
{
{
Ranging
g g is accurate but bearing
g has a 30 degree
g
uncertainty. The object can be located anywhere in the arc.
Typical ranges are of the order of several centimeters to 30
meters.
Another problem is the propagation time. The ultrasonic
signal will take 200 msec to travel 60 meters. ( 30 meters
roundtrip @ 340 m/s )
Tugino, ST MT
STTNAS Yogyakarta
65
Tone Detector
Untuk pengaktifan pada saat star
Tugino, ST MT
STTNAS Yogyakarta
66
33
Polaroid Ultrasonic Sensors
–It was developed for an automatic
camera focusing system
–Range:
Range: 6 inches to 35 feet
Transducer Ringing:
z
z
z
transmitter + receiver @ 50
KHz
Residual vibrations or ringing
may be interpreted as the echo
signal
i
l
Blanking signal to block any
return signals for the first
2.38ms after transmission
Electronic board
Ultrasonic
transducer
http://www.acroname.com/robotics/info/articles/sonar/sonar.html
Tugino, ST MT
STTNAS Yogyakarta
67
Operation with Polaroid Ultrasonic
{
The Electronic board supplied has the following I/0
z
z
z
z
z
INIT : trigger the sensor, ( 16 pulses are transmitted )
BLANKING : goes high to avoid detection of own signal
ECHO : echo was detected.
BINH : goes high to end the blanking (reduce blanking time
< 2.38 ms)
BLNK : to be generated if multiple echo is required
t
Tugino, ST MT
STTNAS Yogyakarta
68
34
{
Ultrasonic Sensors
Applications:
z
z
Distance Measurement
Mapping:
app g Rotating
o a g proximity
p o
y scans
sca s (maps
( aps the
e
proximity of objects surrounding the robot)
Scanning at an angle of 15º apart can achieve best results
Tugino, ST MT
STTNAS Yogyakarta
69
Noise Issues
Tugino, ST MT
STTNAS Yogyakarta
70
35
Global Positioning System (GPS)
24 satellites (+several spares)
bbroadcast
d
time,
i
identity,
id i orbital
bi l
parameters (latitude, longitude,
altitude)
Space Segment
http://www.cnde.iastate.edu/staff/swormley/gps/gps.html
Tugino, ST MT
STTNAS Yogyakarta
71
STTNAS Yogyakarta
72
Thank you!
Tugino, ST MT
36